The present invention relates to particle accelerators and particularly to a particle accelerator powered by a modulated intense relativistic electron beam.
Many different types of accelerators have been proposed over the last 50 years or so.
One type of accelerator is called an "autoaccelerator." In an autoaccelerator, part of an intense relativistic electron beam (IREB) induces an electromagnetic field in a coaxial cavity inserted in a drift tube. This electromagnetic field, in turn, interacts with subsequent portions of the same IREB causing an acceleration of electrons in those subsequent portions of the IREB. See Collective Acceleration of Electrons Using an Autoacceleration Process by T. R. Lockner and M. Friedman in 51 J. Appl. Phys. 6068-6074 (1980), and Autoacceleration of High Power Electron Beams by M. Friedman in 41 Appl. Phys. Lett. 419-421 (1982) for more complete discussions of autoaccelerators.
Another type of accelerator is a proposed wake field accelerator. In such a wake field accelerator two electron beams exchange energy while propagating through the same structure but on different trajectories. The central idea in such an accelerator is to use the wake field, that travels behind a single high-energy bunch of charged particles, to accelerate a low density electron beam. This single bunch has the shape of an annular ring moving down a corrugated drift tube. The wake field produced by this single bunch converges radially along radial transmission lines, establishing an electric field at the center that can be considerably larger than the electric field needed to accelerate the annular ring-shaped bunch. This electric field reaches the center at the same time as the low density electron beam, which is moving axially, causing the low density electron beam to be accelerated.
A third type of accelerator, which is a conventional type of accelerator, is typically an RF (radio frequency) linear accelerator which uses a klystron amplifier. Such klystron amplifiers operate at relatively low output power levels of under 100 megawatts with an efficiency of about 50%. As a result, these typical linear accelerators have to be very large, sometimes three miles in length, in order to accelerate particles to high energy levels.